Power mosfets are ubiquitous in modern electronic systems. They provide the power to motors and actuators in automobiles and to electronic displays including computer terminals and cell phones. There is a constant demand to make electronic systems perform more functions, take us less space and be more reliable. Customers of integrated circuit and mosfet manufacturers want an integrated solution in a single chip or single module that includes not only the power mosfets needed for the system, but also the controller integrated circuit for operating the mosfets. An ideal solution would be a single die that included the power mosfets and their controlling logic circuits. But such a solution has eluded manufacturers because it is difficult for a single die to handle the very different levels of voltage and current for logic and power devices. Logic and controller circuits typically operate in the range of several volts and milliamps, but power mosfets may operate over hundreds of volts and carrying ten of amps. Instead of a single chip solution, a popular compromise is a single package solution where logic and power dies are put into in a single package. That solution is referred to as a multichip module. The following references show examples of multichip modules.
U.S. Published Application 2002/0066950 shows and describes a flip chip multichip module that has two mosfets. The package shows a conventional lead frame where mosfets are bump attached to opposite side of the die pad and the leadframe is then encapsulated in plastic. The publication discloses an alternate embodiment where one die is an integrated circuit controller and the other is a mosfet.
U.S. Pat. No. 5,780,926 shows and describes a multichip package comprising multiple dies and a leadframe. The leadframe has insulating layers on its upper and lower sides and dies on opposite sides are mounted on the insulating layers. The insulating layers and the leadframe have conductive vias with terminals on opposite sides. The dies are wire bonded to the terminals so that the dies on one side are selectively connected to the dies on the other side.
U.S. Pat. No. 6,469,384 shows and describes a semiconductor package without a leads and without a molded body.